hells ehlls hlels lhels elhls lehls hells ehlls hlels lhels elhls lehls hlles lhles hlles lhles llhes llhes ellhs lelhs ellhs lelhs llehs llehs helsl ehlsl hlesl lhesl elhsl lehsl hesll ehsll hsell shell eshll sehll hlsel lhsel hslel shlel lshel slhel elshl leshl eslhl selhl lsehl slehl helsl ehlsl hlesl lhesl elhsl lehsl hesll ehsll hsell shell eshll sehll hlsel lhsel hslel shlel lshel slhel elshl leshl eslhl selhl lsehl slehl hllse lhlse hllse lhlse llhse llhse hlsle lhsle hslle shlle lshle slhle hlsle lhsle hslle shlle lshle slhle llshe llshe lslhe sllhe lslhe sllhe ellsh lelsh ellsh lelsh llesh llesh elslh leslh esllh sellh lselh slelh elslh leslh esllh sellh lselh slelh llseh llseh lsleh slleh lsleh slleh
Note: these 'words' (valid or invalid) are all the permutations of the word hells. These words are obtained by scrambling the letters in hells.